For secondary analysis, multiple analyses will be conducted in multiple steps, with multivariate analyses being conducted first for repeated measures (MANOVA). Correlated measures will be grouped based on conceptual domain (e.g., pain, dyadic adjustment, catastrophizing). Univariate analyses will be conducted if the multivariate results are significant (ANOVA). This will be followed by orthogonal contrasts to examine changes between different measurements. Moreover, we will use exploratory analyses for participants who completed the experimental protocol to determine the effect protocol adherence has on treatment efficacy. Multiple regression analyses will be used to examine the link between socio-demographic variables, pre-treatment dependent variables and pain at post-treatment and 6-months follow-up to identify factors associated with therapeutic success. These latter analyses will be conducted for each treatment group separately. Bonferroni corrections will be used during analyses for multiple comparison adjustments. In the case of missing data, we will explore the effects of withdrawal on sensitivity analyses, replace the missing data with data from the most recent assessment or with averaged or aggregate values.